Torsion springs are used in a wide variety of residential and commercial applications. Perhaps the most common use is in providing a counterbalancing force for overhead doors and the like. In the latter application, a length of torsion spring is coiled around a rotatably mounted horizontal shaft. One end of the spring is tightly threaded on a "cone" or "plug", as it is sometimes called, which is rigidly secured to the torsion shaft and the other end of the spring is fixed in a stationary position. A cable drum is securely fastened to the torsion shaft and a length of cable extends from the drum to the overhead door. As the door is lowered, cable is rolled from the drum, rotating the shaft and placing the spring in torsion, thus storing part of the potential energy due to the weight of the door. In elevating the door, the spring exerts an upward force transmitted through the torsion shaft, drum and cable to assist in raising the door, thus reducing the outside force required.
As previously noted, at least one of the torsion spring ends is normally threaded on a "cone" secured to the shaft. The spring is mounted so as to tighten upon the cone during usage. Should the spring break either as a result of a defect in manufacture or as a result of long usage, it becomes very difficult to remove the broken spring section from the cone. The broken spring section is usually threaded upon the cone so firmly that it becomes necessary to cut the spring with an acetylene torch, which will ruin an aluminum cone in the process; and if a pipe wrench is used to remove the spring, the wrench jaws are easily destroyed.
It is therefore an object of this invention to provide an inexpensive device for easily removing a broken torsion spring section from a cone without the necessity of cutting or burning the cone and leaving same intact for future use.